Suppose That X Has a Distribution With $\mu$ = 21 And $\sigma$

Multiple Choice

Suppose that x has a distribution with $\mu$ = 21 and $\sigma$ = 5. If a random sample is taken of size n = 58, find . $$\mu _ { x } ^ { - }$$

A) 5.00
B) 0.66
C) 2.76
D) 13.81
E) 21.00